GLYCOGENIC FUNCTION OF LIVER 37 



record has existed." Emerson has said: "I am impressed with the 

 fact that the greatest thing a human soul ever does in this world is 

 to see something and tell what it saw in a plain way. Hundreds of 

 people can talk for one who can think, but thousands can think for 

 one who can see. To see clearly is poetry, philosophy and religion all 

 in one." And we might add, that rare quality of mind which enables 

 its possessor to_see clearly is the sine quo non of the true scientist. 



Gastric Digestion — Among Bemard*s earliest investigations was 

 that of gastric digestion. It was important chiefly as a prelude to the 

 momentous discoveries he afterwards made. He was the first to in-) 

 quire into the differences to be found between the digestive appara-i 

 tuses and functions of plant-eating and meat-eating animals — ^between \ 

 the herbivora and camivora. The former thoroughly masticate their 

 food, while the latter bolt theirs. This instinct is explained by the fact 

 that the food of the plant-eating animal contains a relatively large 

 amount of starch, requiring thorough admixture of saliva as an aid to 

 its digestion. Those animals subsisting on meat-protein do not require 

 the aid of the saliva, which accounts for the rapidity with which they 

 devour their food. From this Bernard turned to study the function 

 of the pancreaticjuice. Up to this time the pancreas had been passed.^ 

 over in silSh'ce by the physiologists of the day. He demonstrated its ( 

 three-fold action: **He showed that it, on the one hand, emulsified, \ 

 and, on the other hand split up into fatty acids and glycerine, the } 

 neutral fats that are discharged from the stomach into the duodenum. 

 He proved it had a powerful action on starch, converting it into 

 sugar." The study of the_a£iJiQjajpf ..the^ancreatic juice upon proteins 

 begun by Bernard wasfcontinued by ffiEiiij, his pupil, who investi- 

 gated the action of extracts of the" giandr Pancreatic juice as se- 

 creted does not possess proteolytic powers. This change under normal 

 conditions is brought about by the activating substance, enteroki- 

 nase, contained in the succus entericus producing as soon as the 

 pancreatic juice enters the gut, the change from the inert typsinogen 

 to trypsin, thus acquiring an activity over proteins superior to that 

 of any other digestive juice. (Starling). Up to Bernard's time the 

 principal role of digestion had been confined to the gastric juice. With! j^ 

 his discoveries it became clear that the action of the gastric juice on y 

 the food in the stomach was simply preliminary to intestinal diges- i 

 tion and that the chief work in the preparation of the food for ab- J 

 sorption was accomplished by the pancreatic juice. 



Discovers Glycogenic Function of Liver — Important as were his 

 numerous contributions to our knowledge of physiology, Claude Ber- 

 nard is probably best known as discoverer of the glycogenic function 

 of the liver. The story of his discovery is interesting and well worth 

 relating. The dominant opinion among physiologists when Bernard be- 

 gan his work was to the effect that animals and plants presented a 

 chemical contrast to each other. The plant built up such organic com- 

 pounds as fats, carbohydrates and proteins out of inorganic elements ; 

 the animal feeding on the plant received these organic compounds into 

 its body resolving them into inorganic substances, at the same time 

 using that resolution for the needs of life. While the animal modified 

 vegetable proteins, carbohydrates and fats so as to give them an ani- 

 mal character, it never made anything new. It was maintained that 



